The only time when I have ever seen a monetary value put on saving lives was years ago ( 10- 15 ? ) when there was a debate about trains jumping red signals and the systems that existed to stop trains in those cases.
At the time it was said that the cost was x million and the latest sysem had not been implemented because it was not financially viable based on BR/train company valuation of 500K for a life.
From memory the value was £2.7m and it was set by the Department of Transport and used for road junction improvements as well.